5. Theoretical Physics (CSN4)

Nagy-Soper subtraction for NLO calculations: overview and applications


Aula Seminari (LNF)

Aula Seminari


Via Enrico Fermi, 40 00044 Frascati (Roma)
An alternative subtraction scheme for NLO calculations is presented, based on the formalism developed by Nagy and Soper in a new concept of parton shower with quantum interference. Based on the idea of collective reshuffling of partonic momenta, the new scheme helps to minimize the amount of subtraction terms necessary to match the singular structure of the amplitude. On the other hand, the integration over the phase space of the unresolved parton is challenging due to the structure of the phase space factorization. I will review the main concepts of Nagy-Soper subtraction and explain our semi-numerical strategy to evaluate the integrated subtraction terms for both massless and massive cases. Finally, I will discuss the overall performance of the new scheme in comparison with the standard Catani-Seymour subtraction in a number of practical applications within the HELAC-DIPOLES framework.